Display and labeled article

ABSTRACT

A higher forgery prevention effect is realized. A display includes a first interface section provided with a relief-type diffraction grating constituted by a plurality of grooves, and a second interface section provided with a plurality of recesses or projections arranged two-dimensionally at a center-to-center distance smaller than the minimum center-to-center distance of the plural grooves, and each having a forward tapered shape.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority benefit toU.S. patent application Ser. No. 12/216,536, filed Jul. 7, 2008,allowed, which U.S. application Ser. No. 12/216,536 in turn is acontinuation based on and claiming priority benefit to PCT ApplicationNo. PCT/JP2007/070182, filed Oct. 16, 2007, and which PCT patentapplication is based upon and claims the foreign priority benefit ofJapanese Patent Application No. 2006-288842, filed Oct. 24, 2006, andJapanese Patent Application No. 2007-204651, filed Aug. 6, 2007, theentire contents of each of the foregoing are incorporated herein byreference.

BACKGROUND

1. Field

The present invention relates to a forgery prevention technique.

2. Description of Related Art

It is desirable that authentication articles such as cash cards, creditcards and passports and securities such as gift certificates and stockcertificates be difficult of forgery. For that reason, heretofore, alabel which is difficult of forgery or imitation and which makes it easyto distinguish a genuine article from a forged article or an imitatedarticle has been attached to such an article in order to suppress theforgery.

Further, in recent years, circulation of forged articles is regarded asa problem also with respect to articles other than the authenticationarticles and securities. For this reason, opportunities have beenincreasing to apply the forgery prevention technique mentioned abovewith respect to the authentication articles and the securities to sucharticles.

In Jpn. Pat. Appln. KOKAI Publication No. 2-72320, a display in which aplurality of pixels are arranged is described. In this display, eachpixel includes a relief-type diffraction grating in which a plurality ofgrooves are arranged.

This display displays an image by utilizing diffracted light, and henceit is impossible to forge the display by utilizing the printingtechnique or electrophotographic technique. Accordingly, if this displayis attached to an article as a label for authentication, seeing theimage displayed by the label makes it possible to confirm that thearticle is genuine. Therefore, an article to which this label isattached is hardly forged as compared with an article to which thislabel is not attached.

However, the above-mentioned relief-type diffraction grating can beformed with comparative ease if a device such as a laser is available.Further, in the above display, although a change in the display image iscaused by changing an angle of incidence of the illumination light, anobservation angle or an orientation of the display, the change is not sorich in variety. Therefore, with the development of the technology, theforgery prevention effect of this display is becoming lower.Incidentally, difficulty of forgery or imitation, or ease in distinctionof a genuine article from a forged or imitated article is called here aforgery prevention effect.

SUMMARY

An object of the present invention is to realize a higher forgeryprevention effect.

According to a first aspect of the present invention, there is provideda display comprising a first interface section provided with arelief-type diffraction grating constituted by a plurality of grooves,and a second interface section provided with a plurality of recesses orprojections arranged two-dimensionally at a center-to-center distancesmaller than the minimum center-to-center distance of the plural groovesand each having a forward tapered shape.

According to a second aspect of the present invention, there is provideda display comprising a first interface section provided with arelief-type diffraction grating constituted by a plurality of grooves,and a second interface section constituted by a plurality of regionseach including a plurality of recesses or projections arrangedone-dimensionally or two-dimensionally, wherein one part of the pluralregions and another part of the plural regions are different from eachother in center-to-center distances of the plural recesses orprojections, the minimum center-to-center distance of the plural groovesis equal to or larger than the minimum wavelength of the visible light,and the center-to-center distance of the plural recesses or projectionsis smaller than the minimum wavelength of the visible light.

According to a third aspect of the present invention, there is provideda labeled article comprising the display according to claim 1 or 2; andan article supporting the display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view schematically showing a display according to afirst aspect of the present invention;

FIG. 2 is a cross-sectional view of the display shown in FIG. 1 takenalong the line II-II;

FIG. 3 is a perspective view showing, in an enlarging manner, an exampleof a structure that can be employed for a first interface section of thedisplay shown in FIGS. 1 and 2;

FIG. 4 is a perspective view showing, in an enlarging manner, an exampleof a structure that can be employed for a second interface section ofthe display shown in FIGS. 1 and 2;

FIG. 5 is a view schematically showing a state where the first interfacesection emits diffracted light;

FIG. 6 is a view schematically showing a state where the secondinterface section emits diffracted light;

FIG. 7 is a plan view schematically showing an example of a display, adisplay surface of which is constituted by a plurality of pixelsarranged in a matrix form;

FIG. 8 is a plan view schematically showing an example of an arrangementpattern of recesses or projections that can be employed for the secondinterface section;

FIG. 9 is a plan view schematically showing an example of an arrangementpattern of recesses or projections that can be employed for the secondinterface section;

FIG. 10 is a plan view schematically showing an example of anarrangement pattern of recesses or projections that can be employed forthe second interface section;

FIG. 11 is a plan view schematically showing an example of anarrangement pattern of recesses or projections that can be employed forthe second interface section;

FIG. 12 is a plan view schematically showing an example of anarrangement pattern of recesses or projections that can be employed forthe second interface section;

FIG. 13 is a plan view schematically showing an example of anarrangement pattern of recesses or projections that can be employed forthe second interface section;

FIG. 14 is a perspective view showing, in an enlarging manner, anotherexample of a structure that can be employed for the second interfacesection of the display shown in FIGS. 1 and 2;

FIG. 15 is a perspective view showing, in an enlarging manner, stillanother example of a structure that can be employed for the secondinterface section of the display shown in FIGS. 1 and 2;

FIG. 16 is a perspective view showing, in an enlarging manner, stillanother example of a structure that can be employed for the secondinterface section of the display shown in FIGS. 1 and 2;

FIG. 17 is a plan view schematically showing a display according to asecond aspect of the present invention;

FIG. 18 is a cross-sectional view of the display shown in FIG. 17 takenalong the line XVIII-XVIII;

FIG. 19A is a perspective view showing, in an enlarging manner, anexample of a structure that can be employed for one region of a secondinterface section of the display shown in FIGS. 17 and 18;

FIG. 19B is a perspective view showing, in an enlarging manner, anexample of a structure that can be employed for the other region of thesecond interface section of the display shown in FIGS. 17 and 18;

FIG. 20 is a plan view schematically showing another example of adisplay, a display surface of which is constituted by a plurality ofpixels arranged in a matrix form; and

FIG. 21 is a plan view schematically showing an example of a labeledarticle in which a label for suppressing forgery or a label foridentification is supported by an article.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below in detailwith reference to the accompanying drawings. Incidentally, in thedrawings, constituent elements exhibiting the identical or similarfunction are denoted by the identical reference symbols, and a duplicatedescription will be omitted.

FIG. 1 is a plan view schematically showing a display according to afirst embodiment of the present invention. FIG. 2 is a cross-sectionalview of the display shown in FIG. 1 taken along the line II-II.

This display 10 includes a laminated body of a light transmission layer11 and a reflection layer 13. In the example shown in FIG. 2, the frontsurface side is on the side of the light transmission layer 11, and therear surface side is on the side of the reflection layer 13. Aninterface between the light transmission layer 11 and the reflectionlayer 13 includes a first interface section 12 a, a second interfacesection 12 b, and a third interface section 12 c. As will be describedlater, the first interface section 12 a is provided with a plurality ofgrooves, and the second interface section 12 b is provided with aplurality of recesses or projections.

As a material for the light transmission layer 11, for example, a resinwith optical transparency can be used. For example, when a thermoplasticresin, a thermosetting resin, or a photo-setting resin is used, it ispossible to easily form a light transmission layer 11 provided with aplurality of grooves and a plurality of recesses or projections on onemain surface thereof by transfer using a master.

As the reflection layer 13, for example, a metallic layer made of ametallic material such as aluminum, silver, and alloys thereof can beused. Alternatively, a dielectric material layer with a refractive indexdifferent from that of the light transmission layer 11 may be used asthe reflection layer 13. Further, as the reflection layer 13, alaminated body of dielectric layers in which adjacent layers havedifferent refractive indeces, i.e. a multilayered dielectric film, maybe used. However, it is necessary for one of the dielectric layers incontact with the light transmission layer 11, the dielectric layersbeing included in the dielectric multilayer film, to have a refractiveindex different from that of the light transmission layer 11.

Either of the light transmission layer 11 and the reflection layer 13may be omitted. However, when the display 10 includes both the lighttransmission layer 11 and the reflection layer 13, the interface ishardly damaged and the display can display an image with bettervisibility as compared with the case where the display 10 includes onlyone of them. Particularly, because the second interface section is lowin visible light reflectance due to the structure thereof, the higherthe reflectance of the reflection layer 13 is, the more conspicuous adifference between the second interface section and other sectionsbecomes. Further, by spatially distributing the regions in which thereflection layers 13 are present, it is also possible to express apattern by using the distribution of the reflection layers, for example,by using a contour of the region in which the reflection layer ispresent.

The display 10 further includes an adhesion layer 15 covering thereflection layer 13. When the display 10 includes both the lighttransmission layer 11 and the reflection layer 13, the shape of thesurface of the reflection layer 13 is usually substantially identicalwith that of the interface between the light transmission layer 11 andthe reflection layer 13. When the adhesion layer 15 is provided, it ispossible to prevent the surface of the reflection layer 13 from beingexposed, and hence the plural grooves and the plural recesses orprojections are difficult of duplication. When the side on the lighttransmission layer 11 is the rear surface side and the side on thereflection layer 13 is the front surface side, the adhesion layer 15 isformed on the light transmission layer 11. In this case, not theinterface between the light transmission layer 11 and the reflectionlayer 13, but an interface between the reflection layer 13 and theoutside includes the first interface section 12 a, the second interfacesection 12 b, and the third interface section 12 c. Further, theadhesion layer 15 may be omitted.

FIG. 3 is a perspective view showing, in an enlarging manner, an exampleof a structure that can be employed for the first interface section ofthe display shown in FIGS. 1 and 2. FIG. 4 is a perspective viewshowing, in an enlarging manner, an example of a structure that can beemployed for the second interface section of the display shown in FIGS.1 and 2.

The first interface section 12 a is provided with a relief-typediffraction grating in which a plurality of grooves are arranged. Adistance between centers of the grooves 14 a is within a range of, forexample, 0.5 μm to 2 μm. Further, a depth of the groove 14 a is within arange of, for example, 0.05 μm to 1 μm, and is typically within a rangeof 0.05 μm to 0.3 μm.

Incidentally, it is assumed that the term “diffraction grating” impliesa structure that generates a diffracted wave by being irradiated withillumination light such as the natural light, and includes interferencefringes recorded on a hologram in addition to an ordinary diffractiongrating in which a plurality of grooves 14 a are arranged in parallelwith each other at regular intervals. Further, the groove 14 a or a partbetween grooves 14 a is called a “grating line”.

The second interface section 12 b is provided with a plurality ofrecesses or projections 14 b. These recesses or projections 14 b arearranged two-dimensionally at a center-to-center distance smaller thanthe minimum center-to-center distance of the grooves 14 a. Each recessor projection 14 b has a forward tapered shape. A depth or a height ofthe recess or projection 14 b is normally larger than the depth of thegroove 14 a, and is typically within a range of 0.3 μm to 0.5 μm.

The third interface section 12 c is a flat surface. The third interfacesection 12 c may be omitted.

This display 10 includes the second interface section 12 b provided withthe plural recesses or projections 14 b. As described above, therecesses or projections 14 b are arranged two-dimensionally at acenter-to-center distance smaller than the minimum center-to-centerdistance of the grooves 14 a. That is, this display 10 includes astructure finer than that of the grooves 14 a constituting thediffraction grating at the second interface section 12 b.

It is difficult to accurately analyze such a fine structure from thecompleted display 10. Further, even if the fine structure can beanalyzed from the completed display 10, the display including the finestructure is difficult of forgery or imitation. Although in the case ofthe diffraction grating, the structure is sometimes copied asinterference fringes by an optical duplicating method utilizing laserlight or the like, the fine structure of the second interference section12 b cannot be duplicated.

Further, this display 10 has a very unique visual effect. That is, thefirst interface section 12 a produces diffracted light with wavelengthdispersion and is seen as prismatic colors that cause color-shiftaccording to the viewpoints, and hence, the first interface section 12 ais recognized as a normal interface on which a diffraction grating isformed. Further, when a metallic layer is used as the reflection layer13, in the condition that the diffracted light is not observed, ametallic luster can be observed at the first interface section 12 a asat the third interface section 12 c. Conversely, the second interfacesection 12 b is typically seen as a black printed layer formed as if itoverlaps a part of the diffraction grating. Therefore, it is difficultfor a person trying to conduct forgery or imitation to recognize thefact itself that the fine structure is present at the second interfacesection 12 b.

Accordingly, when this display 10 is used as a forgery prevention label,a high forgery prevention effect can be realized.

The visual effect of this display 10 will be described below in moredetail.

First, a visual effect resulting from the first interface section 12 awill be described.

When the diffraction grating is illuminated, the diffraction gratingemits strong diffracted light in a specific direction with respect to atraveling direction of the illumination light as the incident light.

When light travels in a plane perpendicular to the grating lines of thediffraction grating, an angle of emergence β of m-order diffracted lightcan be calculated by the following formula (1) in which m=0, ±1, ±2, . ..d=mλ/(sin α−sin β)  (1)

In this formula (1), d represents a grating constant of the diffractiongrating, and A represents a wavelength of the incident light and thediffracted light. Further, a represents the angle of emergence of the0-order diffracted light, i.e. of the transmitted light or the regularreflected light. In other words, a is equal in absolute value to theincident angle of the illumination light, and is symmetrical to theincident angle with respect to the Z axis (in the case of thereflection-type diffraction grating). Incidentally, as for a and 13, theclockwise direction from the Z axis is the positive direction.

The most representative diffracted light is the 1st-order diffractedlight. As is evident from the formula (1), the angle of emergence β ofthe 1st-order diffracted light changes according to the wavelength λ.That is, the diffraction grating has a function as a spectroscope.Accordingly, when the illumination light is white light, if theobservation angle is changed in a plane perpendicular to the gratinglines of the diffraction grating, the color perceived by the observerwill be changed.

Further, the color perceived by the observer under a certain observationcondition changes according to the grating constant d.

As an example, it is assumed that the diffraction grating emits1st-order diffracted light in the normal direction thereof. That is, itis assumed that the angle of emergence β of the 1st-order diffractedlight is 0°. Further, it is assumed that the observer perceives this1st-order diffracted light. When it is assumed that the angle ofemergence of the 0-order diffracted light at this time is α_(N), theformula (1) can be simplified to the following formula (2).d=λ/sin α_(N)  (2)

As is evident from the formula (2), in order to allow the observer toperceive a specific color, it is sufficient if a wavelength λcorresponding to the color, an incident angle |α_(N)| of theillumination light, and a grating constant d are set such that theysatisfy the relationship shown by the formula (2). For example, it isassumed that white light including all the light components havingwavelengths within a range of 400 nm to 700 nm is used as theillumination light, and the incident angle |α_(N)| of the illuminationlight is 45°. Further, it is assumed that a diffraction grating in whichthe spatial frequency, i.e., the reciprocal of the grating constant isdistributed within a range of 1000 pcs./mm to 1800 pcs./mm is used. Inthis case, when the diffraction grating is observed from the normaldirection thereof, a part in which the spatial frequency is about 1600pcs./mm is seen blue, and a part in which the spatial frequency is about1100 pcs./mm is seen red.

Incidentally, a diffraction grating in which the spatial frequency issmaller can be formed easier. For this reason, in an ordinary display,most of the diffraction gratings are diffraction gratings of which thespatial frequency is distributed within a range of 500 pcs./mm to 1600pcs./mm.

Thus, the color perceived by the observer under certain observationconditions can be controlled by the grating constant d (or the spatialfrequency). Further, when the observation angle is changed in the aboveobservation conditions, the color perceived by the observer will bechanged.

In the above description, it is assumed that the light travels in aplane perpendicular to the grating line. When the direction of thegrating lines is changed from this state around the normal of thediffraction grating surface, the effective value of the grating constantd with respect to a certain observation direction changes according tothe angle of the grating line with respect to the reference state(hereinafter referred to as an azimuth angle). As a result of this, thecolor perceived by the observer is changed. Conversely, when a pluralityof diffraction gratings different only in the direction of the gratinglines are arranged, it is possible to allow the diffraction gratings todisplay different colors. Further, when the azimuth angle becomessufficiently large, it becomes impossible to recognize the diffractedlight from a certain observation direction, and the observation resultis the same as the case where the diffraction grating is absent. Byutilizing this, and by using diffraction gratings of two types or morewhich are largely different from each other in the direction of thegrating lines, it is also possible to allow them to display imagesindependent from each other when observed from directions correspondingto the respective grating lines.

Further, when the depth of the grooves 14 a constituting the diffractiongrating is made large, the diffraction efficiency will be changed(depending also on the wavelength or the like of the illuminationlight). Further, when the ratio of the area of the diffraction gratingto that of the pixel to be described later is made larger, the intensityof the diffracted light becomes higher.

Accordingly, when the first interface section 12 a is formed byarranging a plurality of pixels, if one part of the pixels are madedifferent from another part of the pixels in the spatial frequencyand/or the azimuth angle of the grooves 14 a, it is possible to allowthe pixels to display different colors, and is possible to setconditions under which observation is enabled. Further, if one part ofthe pixels constituting the first interface section 12 a are madedifferent from another part of the pixels in at least one of the depthof the grooves 14 a and/or the ratio of the area of the diffractiongrating to that of the pixel, it is possible to make the pixels differfrom each other in the luminance. Therefore, by utilizing these, it ispossible to allow the first interface section 12 a to display an imagesuch as a full-color image and a three-dimensional image.

Incidentally, the “image” mentioned herein implies something that can beobserved as spatial distribution of the color and/or the luminance. The“image” includes a photograph, a figure, a picture, a character, a mark,and the like.

Next, a visual effect resulting from the second interface section 12 bwill be described.

FIG. 5 is a view schematically showing the state where the firstinterface section emits diffracted light. FIG. 6 is a view schematicallyshowing the state where the second interface section emits diffractedlight. In FIGS. 5 and 6, 31 a and 31 b denote illumination light, 32 aand 32 b denote regular reflected light or 0-order diffracted light, and33 a and 33 b denote 1st-order diffracted light.

As described above, a plurality of recesses or projections 14 b providedat the second interface section 12 b are arranged two-dimensionally at acenter-to-center distance smaller than the minimum center-to-centerdistance of the grooves 14 a, i.e. the grating constant of thediffraction grating. For this reason, even if the recesses orprojections 14 b are arranged regularly, and the second interfacesection 12 b emits diffracted light 33 b, the observer will not perceivethe diffracted light 33 b simultaneously with the diffracted light 33 afrom the first interface section 12 a having the same wavelength asthese. Particularly, when the difference between the grating constantand the center-to-center distance of the recesses or projections 14 b issufficiently large, the observer cannot perceive the diffracted light 33a from the first interface section 12 a simultaneously with thediffracted light 33 b from the second interface section 12 birrespective of what the wavelength is. However, as is understood fromthe formula (1), when diffracted light of a higher order (|m|≥2) isproduced, it is also possible to enable the diffracted light 33 b fromthe second interface section 12 b to be visually confirmed within aobservation angle range in which the diffracted light 33 a of the higherorder from the first interface section 12 a can be visually confirmed.

Further, each of the recesses or projections 14 b has a forward taperedshape. It has been found that with the forward tapered shape, thereflectance of the regular reflected light of the second interfacesection 12 b is small irrespective of the observation angle.

Accordingly, for example, when the display 10 is observed from thenormal direction thereof, the second interface section 12 b is seendarker than the first interface section 12 a. Further, in this case, thesecond interface section 12 b is typically seen black. Incidentally, theterm “black” implies that the reflectance is 10% or less with respect toall the light components whose wavelengths are within a range of 400 nmto 700 nm when, for example, the display 10 is irradiated with lightfrom the normal direction and the intensity of the regular reflectedlight is measured. Therefore, the second interface section 12 b seems asif it is a black printed layer formed such that it overlaps a part ofthe diffraction grating.

Further, when the angle of emergence of the 1st-order diffracted light33 b from the second interface section 12 b is larger than −90°, theobserver can perceive the 1st-order diffracted light 33 b from thesecond interface section 12 b by appropriately setting the angle formedbetween the normal direction of the display 10 and the observationdirection. Accordingly, in this case, it is possible to visually confirmthat the second interface section 12 b is different from a black printedlayer.

When these configurations are employed, the center-to-center distance ofthe recesses or projections 14 b may be set within a range of, forexample, 200 nm to 350 nm. In this case, as is evident from the formula(1), diffracted light having a wavelength corresponding to the bluecolor can be easily observed at the second interface section 12 b.Therefore, for example, when the first interface section 12 a emitsdiffracted light having a wavelength corresponding to the red color, itbecomes easier to confirm that the display 10 is genuine by thecomparison of these colors.

Incidentally, when the second interface section 12 b is formed byarranging a plurality of pixels, if one part of the pixels are madedifferent from another part of the pixels in at least one of the shape,the depth or the height, the center-to-center distance, and thearrangement pattern of the recesses or projections 14 b, it is possible,as will be described later in detail, to make the pixels differ fromeach other in the reflectance or the like thereof. Accordingly, byutilizing this, a gray-scale image can be displayed on the secondinterface section 12 b.

Further, in this display 10, the first interface section 12 a and thesecond interface section 12 b are in the same plane. Therefore, aconcave structure and/or a convex structure corresponding to the grooves14 a and the recesses or the projections 14 b are formed on one originalplate, and the concave structure and/or the convex structure aretransferred onto the light transmission layer 11, whereby the grooves 14a and the recesses or projections 14 b can be simultaneously formed.Accordingly, when the concave structure and/or the convex structure areformed on the original plate with high accuracy, a problem ofmisalignment between the first interface section 12 a and the secondinterface section 12 b cannot occur. Further, the features of the fineconcave-convex structure and the high accuracy enables high-definitionimage display, and enables easy distinction from those made by the othermethods. The fact that a genuine article can be stably manufactured withvery high accuracy further facilitates distinction between the genuinearticle and a forged article or an imitated article.

As for an image displayed by the display 10, it is advantageous that theimage is constituted by a plurality of pixels arrangedtwo-dimensionally. This will be described below.

FIG. 7 is a plan view schematically showing an example of a displaywhose surface is constituted by a plurality of pixels arranged in amatrix form.

In this display 10, the display surface is constituted by thirty-fivepixels PX11 to PX17, PX21 to PX27, PX31 to PX37, PX41 to PX47, and PX51to PX57, which are arranged in a matrix form (the tenths digitcorresponds to the X direction, and the units digit corresponds to the Ydirection). The pixels PX11 to PX17, PX21, PX27, PX31, PX37, PX41, PX47,and PX51 to PX57 constitute the first interface section 12 a. The pixelsPX22 to PX24, PX26, PX32, PX34, PX36, and PX42 to PX46 constitute thesecond interface section 12 b. The pixels PX25, PX33, and PX35constitute the third interface section 12 c.

The pixels PX11 and PX12 have the same structure, the pixels PX13 toPX15 have the same structure, the pixels PX16, PX17, PX53, PX56, andPX57 have the same structure, the pixels PX21, PX37, PX51, PX52, andPX55 have the same structure, the pixels PX27 and PX41 have the samestructure, and the pixels PX31, PX47, and PX54 have the same structure.Further, the pixel group constituted by the pixels PX11 and PX12, thepixel group constituted by the pixels PX13 to PX15, the pixel groupconstituted by the pixels PX16, PX17, PX53, PX56, and PX57, the pixelgroup constituted by the pixels PX21, PX37, PX51, PX52, and PX55, thepixel group constituted by the pixels PX27 and PX41, and the pixel groupconstituted by the pixels PX31, PX47, and PX54 are different from oneanother in the structure of the diffraction grating. As an example, inFIG. 7, these pixel groups are made different from one another only inthe azimuth angle of the diffraction grating.

Further, the pixels PX22 to PX24, PX26, PX32, PX34, PX36, and PX42 toPX46 have the same structure. Further, the pixels PX25, PX33, and PX35have the same structure.

That is, in the display 10 shown in FIG. 7, the image is constituted bythe eight types of pixels. If the visual effect of each of the eighttypes of pixels is known, an image obtained by rearranging the pixelscan be easily forecast. Therefore, it is possible to determine astructure to be employed for each pixel from digital image data withease. Accordingly, when the image to be displayed on the display 10 isconstituted by a plurality of pixels arranged two-dimensionally,designing the display 10 becomes easy.

Incidentally, in the display 10 shown in FIG. 7, although the image isconstituted by the eight types of pixels, it is sufficient if the numberof types of pixels forming the image is two or more. When the number ofthe types of pixels is increased, a more complicated image can bedisplayed.

Further, in the display 10 shown in FIG. 7, although the image isconstituted by the thirty-five pieces of pixels, it is sufficient if thenumber of pixels constituting the image is two or more. When the numberof the pixels is increased, a more high-definition image can bedisplayed.

In the display 10 shown in FIG. 7, although the first interface section12 a is constituted by the six types of pixels which are different fromone another only in the azimuth angle, the first interface section 12 amay be constituted by a plurality of types of pixels which are differentfrom each other in the structure of the diffraction grating. That is,the first interface section 12 a may be constituted by a plurality oftypes of pixels which are different from each other in at least one ofthe spatial frequency, the azimuth angle, the depth, and the ratio ofthe area of the diffraction grating to that of the pixel of the grooves14 a. Alternatively, the first interface section 12 a may be constitutedby pixels of one type.

Further, in the display 10 shown in FIG. 7, although the secondinterface section 12 b is constituted by the pixels of one type, thesecond interface section 12 b may be constituted by a plurality of typesof pixels which are different from each other in at least one of theshapes, the depth or the height, the center-to-center distance, and thearrangement pattern of the recesses or projections 14 b.

FIGS. 8 to 11 are plan views each schematically showing an example of anarrangement pattern of recesses or projections that can be employed forthe second interface section.

In FIG. 8, the arrangement of the recesses or projections 14 b forms asquare lattice. This structure can be manufactured comparatively easilyby using a micromachining apparatus such as an electron beam drawingapparatus and a stepper, and the center-to-center distance or the likeof the recesses or projections 14 b can be controlled with high accuracycomparatively easily.

Further, in the structure shown in FIG. 8, the recesses or projections14 b are regularly arranged. Accordingly, when the center-to-centerdistance of the recesses or projections 14 is set comparatively long, itis possible to allow the second interface section 12 b to emitdiffracted light. In this case, it is possible to visually confirm thatthe second interface section 12 b is different from a black printedlayer. Further, when the center-to-center distance of the recesses orprojections 14 b is set comparatively short, for example, when is set at200 nm or less, the second interface section 12 b can be prevented fromemitting diffracted light. In this case, as for the observed color, itbecomes difficult to visually confirm that the second interface section12 b is different from a black printed layer.

In FIG. 8, the center-to-center distance of the recesses or projections14 b in the X direction and that in the Y direction are made equal toeach other. However, the center-to-center distances of the recesses orprojections 14 b may be made different in the X direction and the Ydirection. That is, the arrangement of the recesses or projections 14 bmay form a rectangular lattice.

When the center-to-center distances of the recesses or projections 14 bare set comparatively long in both of the X direction and the Ydirection, it is possible to allow the second interface section 12 b toemit diffracted light in both the case where the display 10 isilluminated from a direction perpendicular to the Y direction and thecase where the display 10 is illuminated from a direction perpendicularto the X direction, and is possible to make the wavelength of thediffracted light different from each other in the former case and in thelatter case. When the center-to-center distances of the recesses orprojections 14 b are set comparatively short in both the X direction andthe Y direction, it is possible to prevent the second interface section12 b from emitting diffracted light irrespective of the illuminationdirection. When the center-to-center distances of the recesses orprojections 14 b are set comparatively long in one of the X directionand the Y direction, and are set comparatively short in the other of thedirections, it is possible to allow the second interface section 12 b toemit diffracted light when the display 10 is illuminated from adirection perpendicular to one of the Y direction and the X direction,and prevent the second interface section 12 b from emitting diffractedlight when the display 10 is illuminated from a direction perpendicularto the other of the Y direction and the X direction.

In FIG. 11, the arrangement of the recesses or projections 14 b forms atriangular lattice. When this structure is employed, as in the casewhere the structure shown in FIG. 8 is employed, if the center-to-centerdistance of the recesses or projections 14 b is set comparatively long,it is possible to allow the second interface section 12 b to emitdiffracted light, and if the center-to-center distance of the recessesor projections 14 b is set comparatively short, it is possible toprevent the second interface section 12 b from emitting diffractedlight.

Further, when the structure shown in FIG. 11 is employed, if thecenter-to-center distance of the recesses or projections 14 b isappropriately set, it is possible to prevent the second interfacesection 12 b from emitting diffracted light when the display 10 isilluminated from, for example, the direction A, and allow the secondinterface section 12 b to emit diffracted light when the display 10 isilluminated from the direction B or C. That is, a more complicatedvisual effect can be obtained.

In FIG. 12, recesses or projections 14 b are arranged irregularly. Whenthe recesses or projections 14 b are arranged irregularly, it becomesmore difficult for the second interface section to emit diffractedlight. Incidentally, this structure can be formed by, for example,recording intensity distribution of speckles and utilizing interferenceof light.

In FIG. 13, in addition to the fact that the recesses or projections 14b are arranged irregularly, their sizes are nonuniform. When thisstructure is employed, it becomes more difficult for the secondinterface section to emit diffracted light than in the case where thestructure shown in FIG. 10 is employed.

As exemplified in FIGS. 8 to 13, the arrangement pattern of the recessesor projections 14 b can be variously modified. Further, each arrangementpattern has its inherent visual effect or the like. Therefore, when thesecond interface section 12 b is constituted by a plurality of pixelsdifferent in the arrangement pattern of the recesses or projections 14b, more complicated visual effect can be obtained.

Each of FIGS. 14 to 16 is a perspective view showing, in an enlargingmanner, another example of a structure that can be employed for thesecond interface section of the display shown in FIGS. 1 and 2.

Each of the structures shown in FIGS. 14 to 16 is a modification exampleof the structure shown in FIG. 4. Each of the recesses or projections 14b shown in FIGS. 14 to 16 has a forward tapered shape.

In the structure shown in FIG. 4, the recesses or projections 14 b havea conical shape. When the recesses or projections 14 b are made conical,tips of the recesses or projections 14 b may be pointed, or may have ashape of a truncated cone. However, when the recesses or projections 14b are made pointed conical shape, the recesses or projections 14 b haveno surface parallel with the second interface section 12 b, and hence itis possible to make the reflectance of the second interface section 12 bfor the regular reflected light much smaller than the case where theshape of truncated cones are employed.

In the structure shown in FIG. 14, recesses or projections 14 b have ashape of a quadrangular pyramid. The recesses or projections 14 b mayhave a shape of a pyramid other than the quadrangular pyramid such as atriangular pyramid. In this case, it is possible to enhance theintensity of diffracted light that occurs under a specified condition,thereby further facilitating observation. Further, when the recesses orprojections 14 b have a pyramid shape, tips of the recesses orprojections 14 may be pointed, or may have a shape of a truncatedpyramid. However, when the recesses or projections 14 b have a pointedpyramid shape, the recesses or projections 14 b have no surface parallelwith the second interface section 12 b, and hence it is possible to makethe reflectance of the second interface section 12 b for the regularreflected light much smaller than the case where the shape of truncatedpyramids are employed.

In the structure shown in FIG. 15, the recesses or projections 14 b havea semi-spindle shape. That is, the recesses or projections 14 b have aconical shape rounded at the tip thereof. When the structure shown inFIG. 15 is employed, it is easier to form the convex structure and/orthe concave structure on the master, and transfer the convex structureand/or the concave structure from the master onto the light transmissionlayer 11 than in the case where the structure shown in FIG. 4 or FIG. 14is employed.

In the structure shown in FIG. 16, the recesses or projections 14 b havea structure formed by stacking a plurality of quadrangular prisms havingdifferent base areas one on top of another in the order from the onehaving the largest base area. Incidentally, columnar bodies other thanthe quadrangular prisms such as cylindrical columns and triangularprisms may be stacked in place of the quadrangular prisms.

When the structure shown in FIG. 16 is employed, it is not possible tomake the reflectance of the regular reflected light of the secondinterface section 12 b as small as the case where the structure shown inFIG. 4, 14, or 15 is employed. However, when the structure shown in FIG.16 is employed, as in the case where the structure shown in FIG. 15 isemployed, it is easier to form the convex structure and/or the concavestructure on the master, and transfer the convex structure and/or theconcave structure from the master onto the light transmission layer 11than the case where the structure shown in FIG. 4 or FIG. 14 isemployed.

As described above, the shape of the recesses or projections 14 binfluences the reflectance of the second interface section 12 b.Accordingly, when the second interface section 12 b is constituted by aplurality of pixels different in the shape of the recesses orprojections 14 b, a gray-scale image can be displayed on the secondinterface section 12 b.

When the center-to-center distance of the recesses or projections 14 bis made smaller, the second interface section 12 b becomes seen darker.Particularly, when the center-to-center distance of the recesses orprojections 14 b is made 400 nm or less, as is evident from the formula(2), irrespective of the incident angle of the illumination light, it ispossible to prevent the second interface section 12 b from emittingdiffracted light in the normal direction with respect to all thewavelengths in the range of 400 nm to 700 nm, i.e., the range of thevisible light wavelengths. Therefore, when the second interface section12 b is constituted by a plurality of pixels different in thecenter-to-center distance of the recesses or projections 14 b, agray-scale image can be displayed on the second interface section 12 b.

When the depth or the height of the recesses or projections 14 b is madelarger, the second interface section 12 b becomes seen darker. Forexample, when the depth or the height of the recesses or projections 14b is made equal to or larger than half their center-to-center distance,the second interface section 12 b becomes seen very dark. Therefore,when the second interface section 12 b is constituted by a plurality ofpixels different from each other in the depth or the height of therecesses or projections 14 b, a gray-scale image can be displayed on thesecond interface section 12 b.

When the ratio of a size of the recesses or projections 14 b in adirection parallel with the second interface section 12 b to acenter-to-center distance of the recesses or projections 14 b in thesame direction as the above direction is made nearer to 1:1, the secondinterface section 12 b becomes seen darker. Further, when the size ofthe recesses or projections 14 b in the direction parallel with thesecond interface section 12 b is made equal to the center-to-centerdistance of the recesses or projections 14 b in the same direction asthe above direction, the second interface section 12 b becomes seendarkest. Accordingly, when the second interface section 12 b isconstituted by a plurality of pixels different from each other in theabove ratio, a gray-scale image can be displayed on the second interfacesection 12 b.

Although examples of the case where the first interface section 12 a andthe second interface section 12 b are arranged in the same plane havebeen described above, they may be arranged in different planes. Forexample, first and second light transmission layers are stacked, a firstreflection layer is interposed between them, and the surface of thesecond light transmission layer is covered with a second reflectionlayer. When a metallic layer is used as the first reflection layer, thefirst reflection layer is patterned so that the second reflection layercan be seen from the first light transmission layer's side. Further, atleast a part of an interface between the first light transmission layerand the first reflection layer is made one of the first interfacesection 12 a and the second interface section 12 b, and at least a partof an interface between the second light transmission layer and thesecond reflection layer is made the other of the first interface section12 a and the second interface section 12 b. When such a structure isemployed, the same visual effect as those of the foregoing examples canbe obtained.

FIG. 17 is a plan view schematically showing a display according to asecond aspect of the present invention. FIG. 18 is a cross-sectionalview of the display shown in FIG. 17 taken along the line XVIII-XVIII.

The display 10 shown in FIGS. 17 and 18 has the same structure as thedisplay 10 shown in FIGS. 1 and 2 except that the second interfacesection 12 b includes two regions 12 b 1 and 12 b 2.

FIG. 19A is a perspective view showing, in an enlarging manner, anexample of a structure that can be employed for one region of the secondinterface section of the display shown in FIGS. 17 and 18. FIG. 19B is aperspective view showing, in an enlarging manner, an example of astructure that can be employed for the other region of the secondinterface section of the display shown in FIGS. 17 and 18.

Each of the regions 12 b 1 and 12 b 2 has substantially the samestructure as the second interface section 12 b that has been explainedwith reference to FIGS. 1 to 16. That is, each of the regions 12 b 1 and12 b 2 includes a plurality of recesses or projections 14 b, and theserecesses or projections 14 have a forward tapered shape. Further, theregions 12 b 1 and 12 b 2 differ from each other in the center-to-centerdistance of the recesses or projections 14 b. In the examples shown inFIGS. 19A and 19B, the center-to-center distance of the recesses orprojections 14 b in the region 12 b 2 is larger than that in the region12 b 1 in each of the X direction and the Y direction.

Incidentally, it is not necessary for these recesses or projections 14 bto have a forward tapered shape.

In each of the regions 12 b 1 and 12 b 2, the recesses or projections 14b are arranged regularly or irregularly. Here, it is assumed, as anexample, that the recesses or projections 14 b are arranged in the Xdirection and the Y direction that are perpendicular to each other.

These regions 12 b 1 and 12 b 2 are different from each other in thecenter-to-center distance, i.e. the grating constant of the recesses orprojections 14 b. For this reason, on the basis of the formula (1), itis possible to observe the regions 12 b 1 and 12 b 2 as regions havingdifferent colors, and is possible to make the angle ranges within whichdiffracted light 32 b emitted thereby can be observed different fromeach other. Accordingly, for example, it is also possible, to make theimage displayed on the second interface section 12 b a color image, andto make the image displayed on the second interface section 12 b varyaccording to the observation direction.

In the display 10 shown in FIGS. 17 and 18, it is assumed, for example,that the minimum center-to-center distance of the plural grooves 14 a isequal to or larger than the minimum wavelength of the visible light, andthe center-to-center distance of the plural recesses or projections 14 bis smaller than the minimum wavelength of the visible light. The regions12 b 1 and 12 b 2 are recognized as regions of the black color under theobservation condition that the diffracted light emitted by the regions12 b 1 and 12 b 2 is not observed, and under the above observationcondition, the first interface section 12 a can display, for example, acolor resulting from the 1st-order diffracted light. Further, theregions 12 b 1 and 12 b 2 are recognized as regions of different colorsunder the observation condition that the diffracted light emitted by theregions 12 b 1 and 12 b 2 is observed, and under the above observationcondition, the 1st-order diffracted light emitted by the first interfacesection 12 a can be made not to contribute to display. Accordingly, forexample, it is possible to allow the first interface section 12 a todisplay a color resulting from the diffracted light and to allow thesecond interface section 12 b to display a black color when the display10 is observed from the normal direction thereof, and it is possible toallow only the second interface section 12 b to display a multicoloredimage when the display 10 is observed with the display 10 inclinedlargely. Therefore, it is hardly noticed that the above-mentionedstructure is employed at the second interface section 12 b, and it ispossible to allow the second interface section 12 b to display amulticolored image, for example, a full-color image, and is possible toprevent the recognition of the full-color image from being disturbed bythe first interface section. Conversely, it may be configured such thatthe high-order diffracted light from the first interface section and the1st-order diffracted light from the second interface are observedsimultaneously.

Further, the reflectance or the like of the region 12 b 1 and that ofthe region 12 b 2 may be made substantially equal to each other. Bydoing so, when the display 10 is observed from the normal direction,color senses given to the observer by the regions 12 b 1 and 12 b 2 canbe made substantially equal to each other. Therefore, in this case, bymaking the regions 12 b 1 and 12 b 2 adjacent to each other as shown inFIGS. 1 and 2, a latent image can be formed.

In each of the regions 12 b 1 and 12 b 2, the center-to-center distanceof the recesses or projections 14 b in a first arrangement direction,and the center-to-center distance of the recesses or projections 14 b ina second arrangement direction different from the first arrangementdirection may be identical with each other or may be different from eachother. In the latter case, for example, the 1st-order diffracted lighthaving a wavelength λ emitted by the region 12 b 1 in the directionperpendicular to the X direction and the 1st-order diffracted lighthaving a wavelength λ emitted by the region 12 b 2 in the Y directioncan be made different from each other in the angle of emergence.Accordingly, for example, a color displayed on the region 12 b 1 or 12 b2 when observed from an oblique direction perpendicular to the Xdirection can be made different from a color displayed on the region 12b 1 or 12 b 2 when observed perpendicular to the Y direction by rotatingthe display 10 while maintaining the angle formed by the observationdirection and the normal of the display 10 constant.

Accordingly, for example, it is possible to cause the display colors tobe exchanged between the regions 12 b 1 and 12 b 2, or cause the regions12 b 1 and 12 b 2 to produce different color change. Particularly, thevisual effect of the former case can be easily realized by employingrectangular lattice-like arrangements that are identical with each otherexcept that the azimuth angles are different from each other by 90° forthe recesses or projections 14 b of the region 12 b 1 and the recessesor projections 14 b of the region 12 b 2. Thus, it is possible to obtaina high forgery prevention effect, the color change of which can beeasily grasped by the observer.

FIG. 20 is a plan view schematically showing an example of a displayaccording to a second embodiment in which the display surface isconstituted by a plurality of pixels arranged in a matrix form.

In this display 10, the display surface is constituted by forty-twopixels PX11 to PX17, PX21 to PX27, PX31 to PX37, PX41 to PX47, PX51 toPX57, and PX61 to PX67, which are arranged in a matrix form (the tenthsdigit corresponds to the X direction, and the units digit corresponds tothe Y direction). The pixels PX11 to PX17, PX21, PX27, PX31, PX37, PX41,PX47, PX51, PX57, and PX61 to PX67 constitute a first interface section12 a. The pixels PX22 to PX24, PX26, PX32, PX34, PX36, and PX42 to PX46constitute a first region 12 b 1 of a second interface section 12 b. Thepixels PX52 to PX56 constitute a second region 12 b 2 of the secondinterface section 12 b. The pixels PX25, PX33, and PX35 constitute athird interface section 12 c.

The pixels PX11 and PX12 have the same structure, the pixels PX13 toPX15 have the same structure, the pixels PX16, PX17, PX63, PX66, andPX67 have the same structure, the pixels PX21, PX37, PX61, PX62, andPX65 have the same structure, the pixels PX27, PX41, and PX51 have thesame structure, and the pixels PX31, PX47, PX57, and PX64 have the samestructure. Further, the pixel group constituted by the pixels PX11 andPX12, the pixel group constituted by the pixels PX13 to PX15, the pixelgroup constituted by the pixels PX16, PX17, PX63, PX66, and PX67, thepixel group constituted by the pixels PX21, PX37, PX61, PX62, and PX65,the pixel group constituted by the pixels PX27, PX41, and PX51, and thepixel group constituted by the pixels PX31, PX47, PX57, and PX64 aredifferent from one another in the structure of the diffraction grating.As an example, in FIG. 20, these pixel groups are made different dromone another only in the azimuth angle of the diffraction grating.

Further, the pixels PX22 to PX24, PX26, PX32, PX34, PX36, and PX42 toPX46 have the same structure. The pixels PX52 to PX56 have the samestructure. Further, the pixels PX25, PX33, and PX35 have the samestructure.

When the above configuration is employed, the effect described inconnection with the display 10 shown in FIGS. 17 and 18 can be obtained.Additionally, when the above configuration is employed, the effectdescribed in connection with the display 10 shown in FIG. 7 can beobtained. Incidentally, this display 10 can also be modified in the samemanner as that described in connection with the display 10 shown in FIG.7.

The display 10 described above can be used as, for example, a label forforgery prevention or identification. The display 10 is difficult offorgery or imitation, and hence when this label is supported by anarticle, the labeled article which is a genuine article is difficult offorgery or imitation. Further, this label has the above-mentioned visualeffect, and hence an article whose genuineness is uncertain can beeasily discriminated between a genuine article and a non-genuinearticle.

FIG. 21 is a plan view schematically showing an example of a labeledarticle in which a label for suppressing forgery or a label foridentification is supported by an article. In FIG. 21, printed matter100 is depicted as an example of the labeled article.

This printed matter 100 is a magnetic card, and includes a substrate 51.The substrate 51 is made of, for example, plastic. A printing layer 52and a belt-shaped magnetic recording layer 53 are formed on thesubstrate 51. Further, a display 10 is adhered to the substrate 51 as alabel for forgery prevention or identification. Incidentally, thedisplay 10 has the same structure as that described previously withreference to FIGS. 1, 2, and the like except that the displayed image isdifferent.

This printed matter 100 includes the display 10. Accordingly, asdescribed above, this printed matter 100 is difficult of forgery orimitation. Further, because this printed matter 100 includes the display10, an article whose genuineness is uncertain can be easilydiscriminated between a genuine article and a non-genuine article.Moreover, this printed matter further includes the printing layer 52 inaddition to the display 10, and hence it is easy to contrast the stateof vision of the printing layer 52 with the state of vision of thedisplay. Therefore, an article whose genuineness is uncertain can bediscriminated between a genuine article and an non-genuine articleeasier than in the case where the printed matter does not include theprinting layer 52.

Incidentally, in FIG. 21, although a magnetic card is exemplified as theprinted matter including the display 10, the printed matter includingthe display 10 is not limited to this. For example, the printed matterincluding the display 10 may be other types of cards such as a wirelesscard, an IC (integrated circuit) card, an ID (identification) card, andthe like. Alternatively, the printed matter including the display 10 maybe securities such as a gift certificate and a stock certificate. Stillalternatively, the printed matter including the display 10 may be a tagto be attached to an article, which is to be confirmed as a genuinearticle. Still alternatively, the printed matter including the display10 may be a packaging body or a part thereof for accommodating anarticle to be confirmed as a genuine article.

Further, in the printed matter 100 shown in FIG. 21, although thedisplay 10 is adhered to the substrate 51, the display 10 can besupported by the substrate by other methods. For example, when paper isused as the substrate, the display 10 may be embedded in the paper, andthe paper may be opened at a position corresponding to the display 10.

Further, it is not necessary for a labeled article to be printed matter.That is, the display 10 may be supported by an article including noprinting layer. For example, the display 10 may be supported by anarticle of quality such as a work of art.

The display 10 may be used for purposes other than forgery prevention.For example, the display 10 can also be utilized as toys, tutorials,ornaments, and the like.

What is claimed is:
 1. A display comprising: a first interface sectionformed by arranging a plurality of first pixels and provided with arelief-type diffraction grating constituted by a plurality of grooves,the plural first pixels including two or more pixels different from eachother in at least one of spatial frequency, azimuth angle, depth of theplural grooves, and a ratio of an area of the diffraction grating tothat of the first pixel; and a second interface section formed byarranging a plurality of second pixels, each of the second pixels beingprovided with a plurality of recesses or projections arrangedtwo-dimensionally at a center-to-center distance that is smaller thanthe minimum center-to-center distance of the plural grooves and issmaller than a minimum wavelength of visible light, the plural secondpixels including two or more pixels different from each other in atleast one of shapes, depth or height, center-to-center distance, andarrangement pattern of the plural recesses or projections, the pluralityof recesses or projections each having a forward tapered shape, thefirst and second interface sections being in the same plane.
 2. Thedisplay according to claim 1, wherein the plural recesses or projectionsare identical with each other in shapes, and the arrangement of theplural recesses or projections forms a square lattice or a rectangularlattice.
 3. The display according to claim 1, wherein the pluralrecesses or projections are identical with each other in shapes, and thearrangement of the plural recesses or projections forms a triangularlattice.
 4. The display according to claim 1, wherein the pluralrecesses or projections are arranged irregularly.
 5. The displayaccording to claim 1, wherein each of the plural recesses or projectionshas a pyramidal, conical, or semi-spindle shape.
 6. The displayaccording to claim 1, wherein the center-to-center distance of theplural recesses or projections is 400 nm or less.
 7. The displayaccording to claim 1, wherein the center-to-center distance of theplural recesses or projections is within a range of 200 nm to 350 nm. 8.The display according to claim 1, wherein a depth or a height of theplural recesses or projections is equal to or larger than half thecenter-to-center distance of the plural recesses or projections.
 9. Thedisplay according to claim 1, wherein the plural recesses or projectionshave sizes in a direction parallel with the second interface sectionequal to the center-to-center distances thereof in the direction. 10.The display according to claim 1, further comprising: a lighttransmission layer with a main surface including the first and secondinterface sections; and a reflection layer covering the main surface ofthe light transmission layer.
 11. A labeled article comprising: thedisplay according to claim 1; and an article supporting the display. 12.A display comprising: a first interface section formed by arranging aplurality of first pixels and provided with a relief-type diffractiongrating constituted by a plurality of grooves, the plural first pixelsincluding two or more pixels different from each other in at least oneof spatial frequency, aximuth angle, depth of the plural grooves, and aratio of an area of the diffraction grating to that of the first pixel;and a second interface section constituted by a plurality of regions andformed by arranging a plurality of second pixels, each of the secondpixels including a plurality of recesses or projections arrangedone-dimensionally or two-dimensionally, the first and second interfacesections being in the same plane, one part of the plural regions andanother part of the plural regions being different from each other incenter-to-center distances of the plural recesses or projections, theminimum center-to-center distance of the plural grooves being equal toor larger than the minimum wavelength of the visible light, thecenter-to-center distance of the plural recesses or projections beingsmaller than the minimum wavelength of the visible light, the pluralsecond pixels including two or more pixels different from each other inat least one of shapes, depth or height, center-to-center distance, andarrangement pattern of the plural recesses or projections.
 13. Thedisplay according to claim 12, wherein the plural recesses orprojections are identical with each other in shapes, and the arrangementof the plural recesses or projections forms a square lattice or arectangular lattice.
 14. The display according to claim 12, wherein theplural recesses or projections are identical with each other in shapes,and the arrangement of the plural recesses or projections forms atriangular lattice.
 15. The display according to claim 12, wherein theplural recesses or projections are arranged irregularly.
 16. The displayaccording to claim 12, wherein each of the plural recesses orprojections has a pyramidal, conical, or semi-spindle shape.
 17. Thedisplay according to claim 12, wherein the center-to-center distance ofthe plural recesses or projections is 400 nm or less.
 18. The displayaccording to claim 12, wherein the center-to-center distance of theplural recesses or projections is within a range of 200 nm to 350 nm.19. The display according to claim 12, wherein a depth or a height ofthe plural recesses or projections is equal to or larger than half thecenter-to-center distance of the plural recesses or projections.
 20. Thedisplay according to claim 12, wherein the plural recesses orprojections have sizes in a direction parallel with the second interfacesection equal to the center-to-center distances thereof in thedirection.
 21. The display according to claim 12, further comprising: alight transmission layer with a main surface including the first andsecond interface sections; and a reflection layer covering the mainsurface of the light transmission layer.
 22. The display according toclaim 12, wherein the second interface section is constituted by theplural regions each including the plural recesses or projectionsarranged two-dimensionally, and at least one of said one part of theplural regions and said another part of the plural regions include aregion in which a center-to-center distance of the plural recesses orprojections in a specific arrangement direction is different from acenter-to-center distance in an arrangement direction different from thespecific arrangement direction.
 23. The display according to claim 12,wherein the second interface section is constituted by the pluralregions each including the plural recesses or projections arrangedtwo-dimensionally, and in each of said one part of the plural regionsand said another part of the plural regions, the shape of the pluralrecesses or projections is the same, the center-to-center distances ofthe plural recesses or projections in each of rows that the pluralrecesses or projections form are equal to each other, and thecenter-to-center distances of the plural recesses or projections in eachof columns that the plural recesses or projections form are also equalto each other.
 24. The display according to claim 12, wherein the pluralregions include two or more regions equal to each other incenter-to-center distances of the plural recesses or projections in aspecific direction and different from each other in center-to-centerdistances of the plural recesses or projections in a directionperpendicular to the specific direction.
 25. The display according toclaim 12, wherein each of the plural recesses or projections has aforward tapered shape.
 26. A labeled article comprising: the displayaccording to claim 12; and an article supporting the display.